Method to build robust mechanical structures on substrate surfaces

Abstract

A robust mechanical structure is provided to prevent small foundation structures formed on a substrate from detaching from the substrate surface. The strengthened structure is formed by plating a foundation metal layer on a seed layer and then embedding the plated foundation structure in an adhesive polymer material, such as epoxy. Components, such as spring probes, can then be constructed on the plated foundation. The adhesive polymer material better assures the adhesion of the metal foundation structure to the substrate surface by counteracting forces applied to an element, such as a spring probe, attached to the plated foundation.

1. A method for strengthening connections of a metal foundation on a substrate, the method comprising:
 providing an adhesive material over the substrate contacting sides of the metal foundation, wherein at least one spring probe is mounted on the metal foundation, 
 wherein the metal foundation is formed by:
 patterning using photolithography to form a first metal layer pad; and 
 providing a second metal layer on the pad. 
 
 
   
   
     2. The method of  claim 1 , wherein the adhesive material layer is further provided to contact a portion of a top surface of the first metal layer not covered by the second metal layer. 
   
   
     3. The method of  claim 1 , further comprising:
 providing the adhesive material layer covering all exposed surfaces of the second metal layer; and 
 planarizing the adhesive material layer to expose the second metal layer. 
 
   
   
     4. The method of  claim 1 , wherein the metal foundation is formed separate from the substrate and then attached to the substrate. 
   
   
     5. The method of  claim 1 , wherein the adhesive material comprises an epoxy. 
   
   
     6. A method for strengthening connection of a metal foundation on a substrate, the method comprising:
 providing an adhesive material over the substrate contacting sides of the metal foundation, wherein the metal foundation is formed by patterning using photolithography to form a first metal layer pad; 
 providing a second metal layer on the pad 
 providing the adhesive material layer covering all exposed surfaces of the second metal layer; and 
 planarizing the adhesive material layer to expose the second metal layer; and 
 plating the second metal layer with a third metal layer. 
 
   
   
     7. A method for strengthening connection of a metal foundation on a substrate, the method comprising:
 providing an adhesive material over the substrate contacting sides of the metal foundation, wherein at least one spring probe is mounted on the metal foundation: 
 wherein the metal foundation is formed by the steps of:
 applying a masking material over the substrate; 
 patterning the masking material using photolithography to form an opening; 
 applying a metal in the opening to form the foundation; and removing the masking material. 
 
 
   
   
     8. A method for strengthening connection of a metal foundation on a substrate, the method comprising:
 providing an adhesive material over the substrate contacting sides of the metal foundation, 
 wherein the metal foundation is formed by the steps of:
 applying a masking material over the substrate; 
 patterning the masking material using photolithography to form an opening; 
 applying a conductive metal in the opening to form a sacrificial post; 
 removing the masking material; applying a second masking material; 
 patterning the masking material using photolithography to form a second opening around the sacrificial post; 
 applying a second metal to form the foundation in the second opening; 
 planarizing the adhesive material applied around the foundation along with the first and second metal to expose the first metal; and 
 removing the first metal to leave the foundation with a well. 
 
 
   
   
     9. A method for strengthening connection of a metal foundation on a substrate, the method comprising:
 providing an adhesive material over the substrate contacting sides of the metal foundation, wherein the metal foundation is formed separate from the substrate and then attached to the substrate, 
 wherein the metal foundation is formed and attached to the substrate by:
 providing a sacrificial substrate; 
 patterning using photolithography to form the metal foundation on the sacrificial substrate; 
 attaching the metal foundation to the substrate used to support the metal 
 foundation; and 
 removing the sacrificial substrate. 
 
 
   
   
     10. A method for strengthening connection of a metal foundation on a substrate, the method comprising:
 providing an adhesive material over the substrate contacting sides of the metal foundation, 
 wherein the substrate comprises a multi-layer ceramic with an overlying layer of polyimide. 
 
   
   
     11. A method for strengthening connection of a metal foundation on a substrate, the method comprising:
 providing an adhesive material over the substrate contacting sides of the metal foundation, wherein at least one spring probe is mounted on the metal foundation; 
 wherein the substrate comprises:
 a base material comprising a material selected from a group consisting of: a multi-layer ceramic, a multi-layer organic, a metal matrix, a semiconductor and a metal; and 
 a coating material formed on the base material on which the foundation is formed comprising a material selected from a group consisting of: polyimide, BCB, FR4, ceramic, a polymer, and a filled polymer. 
 
 
   
   
     12. A method for strengthening connection of a metal foundation on a substrate, the method comprising:
 providing an adhesive material over the substrate contacting sides of the metal foundation, wherein at least one spring probe is mounted on the metal foundation; 
 wherein the adhesive material comprises an epoxy filled with a powder to act as a reinforcing agent. 
 
   
   
     13. A method for strengthening connection of a metal foundation on a substrate, the method comprising:
 providing an adhesive material over the substrate contacting sides of the metal foundation, wherein the adhesive material comprises an epoxy filled with a powder to act as a reinforcing agent, 
 wherein the powder comprises at least one in a group consisting of silicon carbide, silicon oxide, silicon nitride, titanium carbide, titanium nitride, titanium oxide, aluminum oxide, and aluminum nitride. 
 
   
   
     14. A method for strengthening connection of a metal foundation on a substrate, the method comprising:
 providing an adhesive material over the substrate contacting sides of the metal foundation, wherein the metal foundation is formed by patterning using photolithography to form a first metal layer pad; 
 providing a second metal layer on the pad; 
 providing the adhesive material layer covering all exposed surfaces of the second metal layer; and 
 planarizing the adhesive material layer to expose the second metal layer; and 
 bonding a wire to the third metal layer; and coating the wire with a resilient material.